Victoria, British Columbia (CNN) -- Colin Baird still remembers the day he got the call from work more than 23 years ago, when he learned of his co-worker's fate.
"We need you to come in," said his colleague from the Sealand of the Pacific in Victoria.
His fellow trainer, 20-year old Keltie Byrne, had slipped and fallen into the orca tank. Byrne was an exceptionally strong swimmer but she was no match for the aquarium's killer whales.
"She tried to get back out and the other girl tried to pull her up, but the whale grabbed her back foot and pulled her under," eyewitness Nadine Kallen told CNN affiliate CTV in 1991. "And then the whales -- they bounced her around the pool a whole bunch of times, and she was screaming for help.
"They tried to grab her with sticks, but they couldn't get her," Kallen said. "And she finally didn't come up any more."
There were three orcas at Sealand at the time -- two females, Haida and Nootka, and Tilikum, the sole male. Tilikum would later become infamous for the 2010 killing of SeaWorld trainer Dawn Brancheau.
Tilikum -- or "Tili," as he was known -- was popular and "very easy to work with," Baird recalled.
"He was very easygoing, he learned quickly, he learned well, very responsive," he said. "You know, he was probably my favorite of the three."
That wasn't the case every day.
"They have personalities, for the lack of a better word, individual personalities, and they have good days and bad days just as we do," Baird said. "There were some days, Tilikum would have a certain look in his eye -- then I would just say, 'Nope, not getting in the water with him today.' "
Beleaguered by the two larger, more dominant females, Tilikum would often be driven away into isolation, his sleek black skin often deeply scored and scraped by Haida and Nootka's sharp teeth.
When Keltie Byrne slipped into the orca tank on February 20, 1991, Sealand needed divers to go into the enclosure with the whales to try to reach her. Baird was one of those divers.
"They had a hard time getting to her," Baird said. "When I arrived, the police suggested that it was a body recovery and not a life-saving effort. And truly that's what it became."
The tragedy rocked Canada.
"People in general couldn't believe what had happened right here in our own backyard," said marine zoologist Anna Hall.
The coroner's inquest into Keltie Byrne's death said she had drowned "due to or as a consequence of forced submersion by orca (killer) whales."
It was the first known time a killer whale had ever killed a human being.
"It was a tough time for all of us," Baird said, referring to the Sealand trainers after Byrne's death. "The next day going back into the pool, and swimming around, and collecting up her clothes and her boots and her whistle and things, and then having to go up and feed the whales and give them their vitamins in the morning, and all of that, I mean it was so surreal."
Baird said he believed wholeheartedly that that it was an accident.
"As best as I can understand it, the three orcas were a little surprised that one of their trainers had seemingly jumped into the pool, although fallen, and they were sort of excited about that, it was something completely out of the norm," he said.
"This wasn't a malicious attack; it was an accident. She had fallen, she had slipped and fell, and taken in a lung full of water. It was not a malicious attack."
Baird believes the orcas recognized something was wrong.
"As soon as she became non-responsive and unconscious in the water, they kept her at the surface," Baird recalled. "You know, they couldn't conceptualize ... that the water was cold, or that she can't hold her breath for 20 minutes. I mean, these things probably don't occur to them. As best as they probably were able to rationalize the situation ... they saw she was in peril and needed help, and so they ... kept her at the surface. And that's behavior that they would exhibit with their own in the wild."
Amid a tidal wave of negative reaction from the public and its own employees, Sealand shuttered its doors the following year, and its three orcas were sold to SeaWorld in the United States.
Years later, Colin Baird would train another killer whale that, just like Tilikum, would gain international attention and profoundly impact the way people viewed killer whales in captivity.
From Tilikum to 'Free Willy'
In 1991, the same year that Keltie Byrne died, Warner Brothers Studios was looking for the star of their next film, "Free Willy."
The casting couldn't have been any more perfect.
"We were location scouting and looking for a seaquarium that would fit the scenario for our film," producer Jennie Lew Tugend said. "It had to be a pretty rundown aquarium where there was essentially one orca whale swimming by himself. And so, many other aquariums did not work. But when we got to Mexico City, we found Keiko."
Keiko, who had been captured off the coast of Iceland in 1979 when he was 3 years old, was in terrible shape. His home in Mexico was too small, too hot and unequipped to deal with a killer whale.
He was lethargic, riddled with skin lesions, had digestive problems, and was extremely underweight.
During the movie's five-week filming period, the crew took steps to improve Keiko's health.
After filming wrapped, producers felt so strongly about the orca they left languishing behind in Mexico, they added a toll-free phone number at the end of the movie with the tagline, "How far would you go for a friend?"
The movie released in 1993 and audiences fell in love with it. Children responded in torrents, sending their lunch money to help the real-life orca.
With the financial backing of Warner Brothers -- also owned by CNN's parent company Time Warner -- and broadcasting magnate Craig McCaw, a plan was developed to try to set the captive whale free.
Colin Baird first met Keiko in Iceland where the whale had finally returned after a staggeringly complicated ballet of logistics. Baird was the project team coordinator, there to teach this killer whale how to hone his killer instinct. After spending most of his life cared for by humans, Keiko needed to learn wild orca behaviors.
As Keiko's confidence grew, so did the stretches of time that he was separated from his trainers. After a particularly violent Icelandic storm, Baird lost sight of him. Outfitted with a transmitter, satellites tracked the killer whale heading in a straight line due north to Norway.
For Baird, that trek proved remarkable -- not just that Keiko made the journey, but that he appeared to have been feeding himself on his own in the wild.
"When I got into the water and measured him in Norway, he was just to the centimeter what he'd been before we had left the bay pen," he said. "That huge massive caloric output every day that he would have had to maintain to swim from Iceland to Norway, we would definitely have seen a marked reduction in his weight, and that simply wasn't the case."
In December 2003, Baird was on vacation when he noticed his voice mail was full of messages from a trainer he worked with on the Keiko project.
"It started out, 'Oh hey, Keiko's acting a bit funny.' Then I would hear the next message and she would be a bit more worried. Then it kept going and by the end she was crying into the phone and then so was I ... just, (tears) coming down right in the middle of the airport."
Keiko had died.
Colin took it hard. "He was perfectly fit and healthy when I left, and his behavior changed very quickly. And he died on a Friday and his behavior really started to change on a Wednesday so he went very quickly. And I was very surprised."
It's believed the 27-year-old orca died of pneumonia.
Keiko was the last killer whale Colin trained. Meanwhile, his other former charge continued to make headlines.
Tilikum kills again
In July 1999, the lifeless body of a man named Daniel Dukes was found lying across Tilikum's back in a SeaWorld Orlando tank. Authorities said it was unclear how Dukes stayed in the park after closing, but that he had shown a "fascination" with the whales previously.
He drowned, and the death was ruled as accidental.
Eleven years later, in front of horrified onlookers, 12,000-pound Tilikum grabbed a hold of SeaWorld trainer Dawn Brancheau and pulled her under.
The killing sparked the making of a documentary acquired by CNN Films called "Blackfish," which explores incidents in aquatic parks leading up to the veteran Brancheau's death.
In response to the film SeaWorld said in a statement to CNN: "Blackfish is billed as a documentary, but instead of a fair and balanced treatment of a complex subject, the film is inaccurate and misleading and, regrettably, exploits a tragedy that remains a source of deep pain for Dawn Brancheau's family, friends and colleagues."
"Perhaps most important, the film fails to mention SeaWorld's commitment to the safety of its team members and guests and to the care and welfare of its animals, as demonstrated by the company's continual refinement and improvement to its killer whale facilities, equipment and procedures both before and after the death of Dawn Brancheau."
When he heard the news in February 2010, Colin Baird said he immediately feared for the orca he once trained in Canada.
"I felt badly for Tilikum, and wondered what his coming days were going be like in terms of, was he going to be secluded off to some pool just used for stud?" Baird said. "You know, there is a certain enrichment that is necessary in captivity, I mean you've got to keep these animals minds busy, you've got to keep working with them, you've got to keep them -- I wouldn't say entertained -- but active, and I wondered what kind of quality of life was he going to have after that incident whether he be relegated to some side pool and forgotten about."
He hasn't seen Tilikum in more than 20 years, but said the incident is a reminder why he got out of the business of working with captive killer whales.
"I think everyone has a better understanding of the natural world, and the intelligence and social infrastructure of these amazing animals -- and that concrete pools are not a place for them to be."
Today, Tilikum is the oldest-living orca in SeaWorld's captivity. According to SeaWorld, he interacts with other whales and makes regular public appearances during shows.